An Obama campaign spokesperson dismissed the online outrage in a statement to The Huffington Post:

"This is mere internet fodder and the picture is not an accurate representation of the diversity of staff, backgrounds and experiences that make up the Obama for America campaign team. This is a campaign built on the inclusion of all Americans and while the Democratic party casts a wide net, the GOP's extreme partisan agenda is turning away voters in droves.”

The reality is that any bias in weeding out volunteers is likely more of a means-test: Volunteers for political campaigns are necessarily college-age kids with enough financial backing to allow them to work full- or part-time (and overtime, in some cases) without pay and with little if any opportunity for advancement. That gives well-off white kids a boost, I suppose.